how to block a vlan

[dchavarria]

                  Please a need your help..!!!...the situation is like this...I have 4 vlan and all has conectivity/access with all (VLAN10,VLAN20,VLAN30 and VLAN40, I use a 3560 Switch for this propose, I need to modificate one vlan (VLAN40) that has access to the rest of the VLAN's BUT the rest of the VLAN's dont have access to VLAN40. I know that it is a problem of access-list BUT I can't undertand how to obtain the result that I like, please help me. Thanks.

David Chavarria M.

[smehrnia]

Hi there,

the need you stated above, sounds to me like you want "VLAN 40" to be able to initiate connections to other vlans and be able to get a response from them, but other VLANs shouldnt be able to initiate a connection towards VLAN40.

if this is the case you could either configure Reflexive Access Lists, or standard/extended permit ACLs with established keyword, you can find detailed explanation in the link below:

http://www.cisco.com/en/US/docs/ios/12_2/security/configuration/guide/scfreflx.html

Hope it Helps,

Soroush.